Which part of a person's eyes are photoreceptors that her see the path in front and the trees around her when she is walking in the woods at night? the lens the cones the rods the pupils?

The answer to this question would be: the rods
The eye have two kinds of photoreceptors, the rod cells and cone cells. Cone cells are used for distinguishing different color. There are three kinds of cone receptors and their interaction make the perception of color.
Rod cells is used for the black and white vision. This cell is more sensitive and only active when the light intensity is low, such as in the night.